A hugely controversial bill to legalise same-sex marriage and adoption goes to France's upper house on Thursday for debate, as opponents prepare to protest out loud or in quiet prayer.
Debate on the bill -- which has already been comfortably adopted by the National Assembly, the lower chamber of parliament -- begins at 1400 GMT in the Senate, and is likely to last until April 12 or 13.
The bill has caused huge controversy in France in recent months, mobilising hundreds of thousands of people in two very separate camps -- pro- and anti-gay marriage -- in nationwide protests, some violent.
Late last month, police in Paris used tear gas to disperse protesters opposed to the legislation and arrested dozens.
While the upper house is unlikely to reject the groundbreaking reform, it is still expected to be a tight vote as the ruling Socialists enjoy a smaller majority in the Senate than in the National Assembly.
Broadly speaking, the Socialists support the proposed reform, as do the Greens, Communists and some centrists.
Some 280 amendments have been introduced for debate, and the right-wing opposition UMP party may put forward a motion asking for the bill to be put to a referendum.
Early on Thursday, opponents registered their protest by turning up at the home of centre-right, pro-bill Senator Chantal Jouanno, blowing whistles and shouting slogans, to try and persuade her to vote against the bill.
Two other anti-gay marriage groups are planning protests later in the day in front of the Senate -- one with whistles, tamtams, tin cans and saucepans, the other involving Catholics praying.
French President Francois Hollande championed same-sex marriage and adoption during his election campaign last year, and his support for the legislation has not wavered throughout the turmoil.
His girlfriend, Valerie Trierweiler, has revealed that the president will be attending the marriages of gay friends once the legislation is on the statute books.